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This study focused on the experimental analysis on drying kinetics of beef in a solar tunnel dryer. During the drying process the parameters of drying air were monitored. Experimental drying curves were then determined. The drying data were fitted to five drying models and their constants evaluated by non-linear regression analysis. Validity of the models was assessed using the coefficient of determination (R2), the reduced chi-square (χ2), mean relative percent error (P) and root mean square error (ERMS). Effective moisture diffusivity (Deff) of beef was also determined. During the drying period, the ambient temperature, ambient relative humidity, inlet air velocity and solar radiation intensity varied from 21.3 to 38.9 °C, 48–69.5%, 0.02–0.18 m/s and 476.3–1000 W/m2 respectively. Temperature profile along the tunnel dryer increased with increased solar radiation and decreased continuously at high moisture content of beef. Whereas drying occurred predominantly in the falling rate period for both drying methods, samples dried in the solar drier had a higher drying rate compared to sun dried beef. The most suitable model for representing the drying characteristics of beef was the Page model. The Deff values for solar tunnel dried beef varied from 2.282 10−10 to 2.536 × 10−10 m/s2.

The objective of the present study was to determine the drying kinetics, moisture diffusivity and sensory quality of convective air dried beef. The effect of temperature of drying (30-60°C) and thickness of samples (2.5-10 mm) on the convective thin-layer drying kinetics of beefdried in a cabinet dryer was evaluated. Five semi-theoretical models were fit to the drying experimentaldata with the aim of predicting drying characteristics of beef and fitting quality of models determined using the standard error of estimate (SEE)and coefficient of determination (R2). Determination ofeffective moisture diffusivity (Deff) from the experimental drying datawas done and sensory quality of the optimized dried cooked and uncookedbeef samplesevaluated. Drying time and rate of drying increased with an increasing temperature but decreased with increased slice thickness. However, there was overlapping of drying curves at 40-50°C. Among the selected models, Page model gave the best prediction of beef drying characteristics. Effective moisture diffusivity (Deff) ranged between 4.2337 x 10-11 and 5.5899 x 10-10 m2/s, increasing with an increase in air temperature and beef slice thickness.Of all the sensory parameters evaluated, texture was the only attribute that gave significantly different (P > 0.05) scores between the cooked and uncooked dried beef samples.

The aim of this study was to investigate the influence of cabinet drying air temperature (30–60 °C) and sample thickness (2.5–10 mm) on the quality attributes of dried beef. The physical (colour, rehydration ratio/RR and texture) and microbial quality of beef samples were evaluated using standard procedures. There was a significant decrease (P ≤ 0.05) in L*, a*, b*and chroma/C* colour values with increasing temperature and beef thickness, while change in thickness had no effect (P > 0.05) on the hue/H* colour attribute. The RR was higher at 60 °C for 5–10 mm thick samples and decreased (P ≤ 0.05) with increase in beef thickness. The firmness values increased with increase in temperature from 30 to 50 °C, decreased at 60 °C and were significantly lower (P ≤ 0.05) at 2.5 mm beef thickness. The total viable counts (TVC) and Staphylococcus aureus numbers in beef dried at 30 and 40 °C were higher than that of fresh beef, whereas drying at 60 °C significantly (P ≤ 0.05) reduced the microbial numbers.

Gluten-free batter and bread was prepared from modified cassava starch, sorghum and amaranth flour. Heat-moisture treatment (80°C, 18, 24 or 30% moisture content, and 8, 16 or 24 h incubation) of cassava starch increased its crystallinity, onset pasting temperature and water absorption index; and decreased its swelling power, water solubility index and peak viscosity. Heat-moisture treated cassava starch was made into batter with sorghum and amaranth in the ratio of 50:40:10. The other ingredients, weighed on flour-weight-basis, were water (75%), sugar (6.7%), fat (2%), salt (1.7%), and amaranth malt at 0, 1 or 2.5%. The interaction effect (that is, starch modification x amaranth malt) significantly (P ≤ 0.05) affected batter consistency. Breads made from heat-moisture treated starch were softer than those containing native starch. The interaction effect (that is, starch modification x amaranth malt) was significant (P ≤ 0.05) only for the texture profile analysis property of cohesiveness. Further investigation of the effect of heat-moisture treatment showed that the interaction effect (that is, moisture content x incubation time) significantly (P ≤ 0.05) affected only the Texture Profile Analysis properties of hardness and chewiness. Key words: Amaranth, cassava, gluten-free bread, heat-moisture treatment, malt, sorghum.